In the medical profession it is recognized that it is necessary, in the event of a cardiac arrest, to assist the heart in its pumping function until effective spontaneous cardiac contraction can restore normal blood circulation. During cardiac arrest, the pumping action of the heart ceases and blood flow stops. If blood flow or circulation is not sustained or reinstituted, either by restoration of spontaneous cardiac activity or by some other provision of artificial circulatory support, irreversible vital organ damage and clinical death will ensue.
Currently, several method are employed to sustain circulation during cardiac arrest. These methods include closed chest external and open chest internal cardio-pulmonary resuscitation (CPR) techniques. All of the external CPR techniques, as well as the devices which are used therewith, rely on depressing the sternum producing a generalized increase in intrathoracic pressure. This produces a low level of blood flow to the organs of the body. However, none of these external. CPR devices nor their related techniques, develop enough direct mechanical compression of the ventricular chambers of the heart to produce physiologically significant blood flow. Open-chest, bi-manual cardiac compression, in which the heart is directly compressed by the hands of the operator, produces far more blood flow than any method of closed chest CPR. It is capable of supplying vital organs with more blood and produces a higher probability of survival than any method of closed chest CPR. During open-chest, internal CPR, an anterior-lateral chest incision is commonly used with the surgical incision being large enough to accommodate introduction into the chest cavity of both hands of an operator, so that a manual compression of the heart muscle may take place.
Both the external (closed chest) CPR and open chest techniques can be performed manually or with the aid of mechanical devices. With either technique, the goal is to maintain artificial circulation, including circulation through the heart itself, until spontaneous cardiac activity can be restored. This restoration almost always involves electrical defibrillation of the heart in which a direct current shock is administered to the heart muscle to restore its spontaneous contraction.
A method of performing internal CPR is described in U.S. Pat. No. 3,496,932 of Prisk et al. issued, Feb. 24, 1970. This described method uses a small surgical incision, about one (1) inch, to accommodate the placement of a direct mechanical compression device on the heart muscle. The compression device comprises a generally cone-shaped plastic film serving as an inflatable and deflatable bladder which is connected to an air supplying stem which, in turn, is attached to an external pneumatic apparatus.
In the method of the '932 patent, a surgical incision is made in the upper abdomen below the lower tip (xiphoid) of the sternum for the purpose of introducing the device which is placed behind the sternum onto the heart. Before such an introduction, a trocar carrying a large tube and having a pointed tip is inserted into the incision, in an upward manner, into the space between the sternum and the anterior aspect of the pericardium, or alternatively into the pericardial sac itself. Entrance of this device carrying a sharp tip between the posterior aspect of the sternum and anterior aspect of the heart involves risk of accidently wounding the heart. After insertion, the tip of the trocar is moved until the desired location for the later placement of the inflatable/deflatable bladder on the heart is reached. Then, the trocar is withdrawn but the large tube carried by the trocar remains, allowing for the bladder to be inserted through the tube and onto the heart ready for periodic pneumatic inflation and deflation cycles of the bladder. These cycles are accomplished with the assistance of a mechanical pump apparatus to produce corresponding compression/relaxation cycles of the heart muscle to produce an artificial circulation during cardiac arrest.
Although the '932 patent may advantageously accomplish mechanical compression/relaxation of the heart by means of a small surgical incision so as to avoid an open-chest procedure, it is desired that such compression/relaxation be accomplished by a self-contained heart massager device having no reliance on any external mechanical device. Moreover, it is desired that a heart massager be positioned on the heart without the need for any sharp probing tip that might damage contacting elements of the body because of inadvertent contact therewith. Further, it is desired that the heart massager not only be devoid of a pointed tip but also have relatively small dimensions for insertion into the chest and a contoured surface for mating with the heart. Still further, it is desired that a heart massager be provided having collapsible features so as to minimize the size of the surgical incision needed for the introduction of the massager into the chest.
It is further desired that a method for inserting the heart massager be provided so that a surgical incision is not made through the abdomen.
It is still further desired, that means be provided to allow the heart massager to be guided to not only its most desirable/optimum position on the heart, but also be monitored and maintained at such a position during the direct mechanical compression of the heart muscle. Moreover, it is desired that the heart massager be provided with means to allow the massager to be re-positioned during use so that an optimum hemodynamic compression of the heart muscle and maximal blood flow to vital organs may be obtained during the massage and until spontaneous cardiac action can be restored.
Further, it is desired that the heart massager have provisions to accommodate direct cardiac defibrillation, detection of any abnormal electrocardiograph rhythm that might occur during the heart massage, and means for stabilizing any irregular heartbeats that might occur during the cardiac arrest condition.
Accordingly, it is an object of the present invention to provide a massager having no reliance on any external mechanical device apart from the massager per se to accomplish a direct massage of the heart muscle.
Another object: of the present invention is to provide a heart massage that is not only devoid of a sharp tip that may unnecessarily and inadvertently damage body elements but also has relatively small dimensions and a contoured surface for mating with the heart.
It is a further object of the present invention to provide a massager having collapsible features so as to hold to a minimum the size of the surgical incision needed for the subcutaneous introduction of the massager onto the heart.
Still further it is an object of the present invention to provide a device having provisions for endoscopic (optical) guidance means so as to allow the massager to be initial positioned on the heart as desired to perform the massage, to be maintained at that initial position or to be repositioned during the massage so as to accomplish hemodynamically optimal compression of the heart.
Further still, it is an object of the present invention to provide a device having provisions to accomplish cardiac defibrillation, while at the same time allowing for the detection of abnormal electrocardiograph rhythms, or if needed, provisions for stabilizing the heartbeats during cardiac arrest by electrical cardiac pacing.